Field of Endeavor
The present disclosure relates to a method for measuring a thickness of thin film using x-ray and an apparatus using the same, and more particularly to a method for measuring thickness of thin film layer using x-ray configured to use a special component included in base layer and/or thin film layer of a reference sample and a target sample and an apparatus thereof, and more further particularly to a method for measuring a thin nanometer-level film thickness using x-ray without destructing a target sample, and an apparatus using the method.
Background
This section provides background information related to the present disclosure which is not necessarily prior art.
The thin film thickness is conventionally measured by individually using an SEM (Scanning Electron Microscope), an FESEM (Field Emission Scanning Electron Microscope), an STEM (Scanning Transmission Electron Microscope), an eddy current sensing method, an ultrasonic method and a high energy sensitive method using X-ray, or in combination with each other. Among these methods, the X-ray using method is such that X-ray is irradiated to a target object such as film or thin film formed with a metal thin film and/or polymer to measure thickness using non-contact method in response to intensity of a signal obtained therefrom. The thin film thickness measuring method using X-ray may use a single object as a target or an object under production as a target.
For example, a thickness of a target object such as a metal thin film or a film can be measured in real time while the target object with a predetermined thickness is being manufactured by rolling method, one of the methods of manufacturing the target object, and a good quality of products can be manufactured with a constant even thickness by adjusting the thickness of the target object.
The non-contact thickness measuring device using X-ray may be such that an amount of quantum X-rays penetrating a target object is detected by a detector, or an amount of fluorescent X-rays penetrating a target object is detected to measure the thickness of the target object. The amount of quantum X-rays or the amount of fluorescent X-rays detected by the detector is changed by absorption coefficient, density and thickness in response to material of the target object, where an amount of quantum X-rays irradiated to and emitted from an X-ray target without a target object and an amount of X-rays irradiated to through a target object and emitted from the X-ray target through the target object are relatively compared, whereby a thickness of the target object can be learned by checking a relative difference therebetween.
However, the method of measuring a thickness of a target object by a difference of quantum amount emitted when a target is present and when a target object is absent using the X-ray suffers from disadvantages in that a basic premise is required of learning a difference of amount of quantum when a target object is absent such that it is difficult to apply this method to measurement of thickness alone formed on a substrate or a base layer, or to continuous process. Particularly, even if a sensitive X-ray method is used to a high energy, and if a thin film thickness is under several nanometers (nm), it is difficult to measure the thin film thickness of nanometer level.
Thus, there is a need to address the abovementioned disadvantages.